MOSCOW, Feb 18 (Reuters) - Dmitry Medvedev, deputy

chairman of Russia's powerful Security Council, said on Tuesday

that a Ukrainian drone strike on an oil pipeline in Russia could

disrupt flows to world markets and damage U.S. companies.

A drone strike has hit a pumping station on a oil pipeline

in Russia, reducing flows from Kazakhstan to world markets

pumped by Western firms including Chevron ( CVX ) and Exxon

Mobil ( XOM ), its operator said on Monday.

The operator, the Caspian Pipeline Consortium (CPC), said

drones struck the Kropotkinskaya station in the southern

Krasnodar region, where work was halted to investigate the

damage.